Felsenstein＇s ＂one-allele model＂ of speciation： The role of philopatry in the initial stages of host plant mediated reproductive isolation in Enchenopa binotata  

作　　者：Frank W. STEARNS Kelley J. TILMON Thomas K. WOOD 

机构地区：[1]Department of Biology, Biology-Psychology Building, University of Maryland, College Park, MD 20742, USA [2]Department of Plant Science, Plant Science Building, South Dakota State University, Brookings, SD 57007, USA [3]Department of Entomology and Applied Ecology, 250 Townsend Hall, University of Delaware, Newark, DE 19716, USA

出　　处：《Current Zoology》2013年第5期658-666,共9页动物学报（英文版）

摘　　要：The study of speciation genetics is primarily concerned with identifying the genetic traits that allow divergent selec- tion to overcome the homogenizing effects of gene flow. Felsenstein reviewed this race between gene flow and selection, con- cluding that speciation with gene flow was unlikely under a ＂two-allele model＂ （where two traits were necessary for reproductive isolation） but that divergence could occur quite easily under a ＂one-allele model.＂ Despite this finding, much of the sympatric speciation research involving phytophagous insects has relied on a two-trait model, where insects evolve both preferences for and increased performance on novel host plants. Philopatry （a tendency to remain where one was born） is known to occur in phyto- phagous insects and is a single trait isolation mechanism. However, it is traditionally invoked as simply augmenting reproductive isolation. Species in the Enchenopa binotata complex are believed to have speciated in sympatry. They exhibit host plant prefe- rences, host specific performance advantages and strong philopatry. We experimentally shifted E. binotata to evolutionarily novel host plants. Previous research has demonstrated that the experimental population of insects possesses genetic variation in prefe- rence and performance to the novel host. The degree of philopatry at mating and egg-laying was assayed for the first four years under full choice conditions. Host plant preference and performance was assayed after eight years. Philopatry was an immediate and strong isolating mechanism, while preference for and performance on the novel host lagged. We therefore suggest that philo- patry may be a more important mechanism in the early stages of a host shift than previously believed [Current Zoology 59 （5）： 658-666, 2013].

关 键 词：PHILOPATRY Enchenopa Ecological Speciation Sympatric Speciation 

分 类 号：S433.3[农业科学—农业昆虫与害虫防治] TS103[农业科学—植物保护]